Is there any way to reduce 5th gear RPM on a 79 GS850

[79GS850VETTER]

I have a 79 GS 850 (shaft drive). With the speeds of highways these days my co-riders usually like to run at about 130 to 140 km/h. My bike is reving high at that speed and I would like a taller 5th gear for the final drive. Being shaft drive I can't simply change a sprocket. Can I change a gear in the trans? Someone said to put a taller rear tire on. I'm not sure I like that idea and I don't think that would change things significantly. Any suggestions?

 

[SqDancerLynn1]

Your stuck with what you have. There is no way to change the gear ratio. The only possible way is to change the rear diff for one from an 83-84 1100GK some, not all had a 2.9 ratio instead of the standard 3.1. It will only make 300-400 rpm difference

 

[79GS850VETTER]

Thanks for the advice. I was afraid that it was not changable. I'm going to look into changing the rear diff...even 3-400 rpm would help. That or switching out the engine for an 1100. Do you know if any years/models would be better than others?

 

[tkent02]

The engine is made to spin, RPM won't hurt it.
Unless you want to sound like a Harely or something.

 

[Nessism]

All 1983+ GS1100 shaft drive bikes have the 2.9 rear end. It makes a noticeable difference and doesn't cause engine lugging. Suzuki should have done that from the start, or added a 6th gear. It won't hurt to rev the engine, but it does get a little annoying.

 

[79GS850VETTER]

Thanks. The RPM is not bad for a while but 600 mile days would be nicer if it was reving lower and not vibrating so much. I did not know you could ad a 6th gear. Is there a kit available or how is it done?

 

[dpep]

Thanks. The RPM is not bad for a while but 600 mile days would be nicer if it was reving lower and not vibrating so much. I did not know you could ad a 6th gear. Is there a kit available or how is it done?

Suzuki could have (should have) added a sixth gear when they designed and built the bike. You can't now, not practically.

 

[Guest]

Sync your carbs. This will cut the vibration.

 

[Colin Green]

Thanks for the advice. I was afraid that it was not changable. I'm going to look into changing the rear diff...even 3-400 rpm would help. That or switching out the engine for an 1100. Do you know if any years/models would be better than others?

Switching engines isn't that straight forward. The shaft will also have to be replaced, and I believe the carbs and airbox also need to be swapped. Easier to just do the diff. Good luck

 

[Guest]

Buy a chain drive 1100.:-#

 

[79GS850VETTER]

sounds like rear diff is the most reasonable approach. I'll start looking for one. If I get one in I'll let you know how it went. Thank you all for your suggestions.

 

[shirazdrum]

Thanks. The RPM is not bad for a while but 600 mile days would be nicer if it was reving lower and not vibrating so much. I did not know you could ad a 6th gear. Is there a kit available or how is it done?

600 mile days? where are you going bro? Hell i live off of my bike and still don't go 600 miles.

 

[bwringer]

600+ mile days on a GS850:

1) Manic Salamander bar end weights.

2) Twist that grip on the right as needed.

3) Stop whining. The engine loves to spin. So let it spin.

 

[TheCafeKid]

600+ mile days on a GS850:

1) Manic Salamander bar end weights.

2) Twist that grip on the right as needed.

3) Stop whining. The engine loves to spin. So let it spin.

Hey Brian, any recommendations on a good set of bar end mirrors that would allow me to use those fancy bar end weights? My horizontally challenged shoulders prevent any use whatsoever out of the stock mirrors, (plus I think they look hideous on the 1100E personally) but I would love to have some weights out there...

 

[49er]

sounds like rear diff is the most reasonable approach. I'll start looking for one. If I get one in I'll let you know how it went. Thank you all for your suggestions.

I'm running an '83 GS1100 diff in my GS850GN. With the new 2.9-1 ratio, the engine rpm in 5th gear at 100 kph, dropped from 4500 to 4100.

If you want to further reduce the rpm in 5th gear, you need to split the cases and fit the higher ratio 5th gear set from a '83 onwards 850 or 1100. This change will reduce the rpm at 100 kph a further 400 rpm (3700). I have bought a new 5th gear set myself and will fit them to my spare engine, a monster big bore 850 project soon to be started.

 

[Guest]

I'm running a '83 GS1100 diff in my GS850GN. With the new 2.9-1 ratio, the engine rpm in 5th gear at 100 kph, dropped from 4500 to 4100.

If you want to further reduce the rpm in 5th gear, you need to split the cases and fit the higher ratio 5th gear set from a '83 onwards 850 or 1100. This change will reduce the rpm at 100 kph a further 400 rpm (3700). I have bought a new 5th gear set myself and will fit them to my spare engine, a monster big bore 850 project soon to be started.

You go Ian!
I'm painting the cases on Monday. I'm still asking the wifes forgiveness!

 

[49er]

You go Ian!
I'm painting the cases on Monday. I'm still asking the wifes forgiveness!

Hey Bill, it's always easier to ask forgiveness than to gain permission in the first instance! Besides, the making up is usually well worth it.

Ya haven't been using her oven to do the paint baking have ya?:dancing:

 

[Guest]

Hey Bill, it's always easier to ask forgiveness than to gain permission in the first instance! Besides, the making up is usually well worth it.

Ya haven't been using her oven to do the paint baking have ya?:dancing:

A man has to know his limitations.

 

[Colin Green]

I'm running an '83 GS1100 diff in my GS850GN. With the new 2.9-1 ratio, the engine rpm in 5th gear at 100 kph, dropped from 4500 to 4100.

If you want to further reduce the rpm in 5th gear, you need to split the cases and fit the higher ratio 5th gear set from a '83 onwards 850 or 1100. This change will reduce the rpm at 100 kph a further 400 rpm (3700). I have bought a new 5th gear set myself and will fit them to my spare engine, a monster big bore 850 project soon to be started.

Hey Ian Cool 5th gear option, but my 85 GS1100G does 4000rpm at 100? does that mean that mine is an oddity? Did you also change your shaft when you put the 1100 diff in?

 

[Steve]

Hey Ian Cool 5th gear option, but my 85 GS1100G does 4000rpm at 100? does that mean that mine is an oddity?

No, being an '85, it already has the taller gear ratios. I think the 1100s also had some taller intermediate gearing, as they turned fewer revs than the 850s all along.

.